This proposal is directed to the Recovery Act Limited Competition, High-End Instrumentation Grant Program (S10) Program Announcement (PA) Number: PAR-09-118. Funds are requested to upgrade the Bruker 750 MHz NMR spectrometer located in the National Magnetic Resonance Facility at Madison (NMRFAM), University of Wisconsin-Madison. For a fraction of the cost of the original system, this aging spectrometer can be brought back to current specifications and made to be compatible with the current pulse programs and automation demanded by users. This request will support the rebuilding of the cryostat that houses the superconducting solenoid (renewed O-rings and seals), a new controller for the pumping system that keeps the system at field (to replace a unit that is failing and is no longer supported by the vendor), a new console that will provide improved sensitivity, more flexible pulse programming, dual receivers, improved variable temperature operation, and rebuilding of the compressor for the cryoplatform that supports the cryogenic probe. This NMR spectrometer is heavily used by NIH-funded research groups at the University of Wisconsin-Madison and other institutions. Of the Bruker spectrometers at NMRFAM, the 750 MHz has the highest field and is the most heavily used NMR spectrometer. It is favored by users who are more comfortable with this brand. The user base has NIH funded research projects a variety of areas of biomedical interest. PUBLIC HEALTHE RELEVANCE: Funds are requested to upgrade a key NMR spectrometer (Bruker 750 MHz) in the National Magnetic Resonance Facility at Madison to correct serious problems with its reliable operation and to bring it up to current standards of sensitivity, pulse programming flexibility, and automation. Modernization of the instrument will fulfill the demands from users on and off campus for the NMR data collection capability needed to carry out their NIH-funded biomedical research projects.